Dendritic Cell-based Immunotherapy Pulsed With Wilms Tumor 1 Peptide and Mucin 1 as an Adjuvant Therapy for Pancreatic Ductal Adenocarcinoma After Curative Resection: A Phase I/IIa Clinical Trial

Background/Aim: We evaluated the safety, feasibility, and preliminary efficacy of Wilms tumor gene 1 (WT1) peptide and Mucin 1 (MUC1)-pulsed dendritic cell (DC) (WT1/MUC1-DC) vaccination as an adjuvant immunotherapy for surgically resectable pancreatic ductal adenocarcinoma (PDA) patients. Patients and Methods: Eligible patients were administered WT1/MUC1-DC vaccination at least seven times every 2 weeks with concomitant adjuvant chemotherapy after surgical resection of PDA. Results: Ten patients were enrolled and no Grade 2 or higher toxicities were associated with DC vaccination. The estimated overall survival (OS) and relapse-free survival (RFS) at 3-years from the time of surgical resection were 77.8% and 35.0%, respectively. Immunohistochemical analysis suggested a possible relationship between induction of WT1-specific cytotoxic T lymphocyte after DC vaccination and higher infiltration of CD3/CD4/CD8 lymphocytes in tumor tissues. Conclusion: WT1/MUC1-DC vaccination in the adjuvant setting was safe and well-tolerated in PDA patients after tumor resection. A large-scale prospective study is warranted to evaluate the clinical benefit of this modality.